June 5, 2010 AT 5:44 pm

Spatialization Station

The goal of all of this was to have a controller with a 16 joystick interface that I could then use in Max/MSP, as that is my main audio programming environment. I work a lot with multi-channel audio and large speaker arrays, so I’ve always wanted a controller that could really take advantage of that.

Inside the box I mounted 16 analog joysticks. Each joystick has two pots (one for x, one for y). Each pot has three connections (V+, ground, and output voltage). All of the power connections are routed to a couple of small circuit boards so the wiring doesn’t need to be traveling all over the place.

No Arduino board has the necessary 32 analog pins to read all of the joystick outputs individually, so I had to use some multiplexers to cut down on analog pin usage. Each row of joysticks goes to one 4051 eight-channel multiplexer. The output from each multiplexer goes to one of the analog pins on the Arduino board. The code I wrote for the Arduino board takes care of iterating through all eight inputs on the multiplexers, reading their values, and spitting it out as a list.

The painful part was the Max/MSP code. There were a lot of examples of multiplexing with Arduino scattered around the internet, so piecing that part together wasn’t so difficult. It just seemed as though nobody else was interested in getting multiplexed data from an Arduino into Max/MSP, so I had a fun time getting that working properly. Max just sees the Arduino’s output as raw serial data, so I had to write a Max patch that took this data and parsed it into useable numbers.

Once I got it all wired up and coded though, it was worth it. It’s pretty rock solid. There’s very little jitter/hiccups from the joysticks and I now get 10-bit (0-1023) resolution (as opposed to MIDI’s 0-127) in my Max patches.

And since it’s all going into Max/MSP, the joysticks don’t need to be dedicated solely to the spatialization of audio. The data can be mapped to whatever I please. Though, I did have fun flinging 16 simultaneous sounds around the room over an 8-speaker array at the box’s stage debut.

"In considering any new subject, there is frequently a tendency, first, to overrate what we find to be already interesting or remarkable; and, secondly, by a sort of natural reaction, to undervalue the true state of the case, when we do discover that our notions have surpassed those that were really tenable" - Ada Lovelace